Pressure control device for a rolling mill



J. w. OBRIEN 3,355,926

PRESSURE CONTROL DEVICE FOR A ROLLING MILL Dec" 5, 1967 5 Sheets-Sheet 1Filed Sept. 21, 1964 INVENTOR. JEQEMMA/ 14 owe/EA,"

BY 74 Q 7114:; ATTORNE) Dec. 5, 1967 J, w, 3,355,926

PRESSURE CONTROL DEVICE FOR A ROLLING MILL Filed Sept. 21, 1964 3Sheets-Sheet 2 X4759; flwim ATTOR/VEV.

Deb. 5, 1967 J. w. O'BRIEN PRESSURE CONTROL DEVICE] FOR A ROLLING MILLFiled Sept. 21, 1964 5 Sheets-Sheet 3 INVENTOR.

JEREMIAH 14 OER/EN ATTORNEY.

United States Patent 3,355,926 PRESSURE CONTROL DEVICE FOR A ROLLINGMILL Jeremiah Wagner OBrien, Mount Lebanon, Pa., assignor to UnitedEngineering and Foundry Company, Pittsburgh, Pa., a corporation ofPennsylvania Filed Sept. 21, 1964, Ser. No. 397,981 Claims priority,application Great Britain, Oct. 7, 1963, 39,371/63 2 Claims. (Cl.72-245) ABSTRACT IF THE DISCLOSURE A control valve for a roll adjustingsystem in a rolling mill having a pair of piston-cylinder assemblies atopposite ends of the roll and a relief valve for each assembly. Thecontrol valve permits simultaneous adjustment of the relief valves bymeans of two sets of gearings mounted on a pair of rotatable and axiallydisplaceable shafts, each of Which is operatively connected to one ofthe relief valves. One set of gearings is rotated by means of ahandwheel to effect rotation of the two shafts in opposite directionsand thus to establish unequal outlet pressures from the two valves. Theother set of gearing has a locking arrangement which is released whenthis gearing is to be rotated by a second handwheel to effect rotationof the two shafts in the same direction and thus identically raise orlower the outlet pressure from the two relief valves.

The present invention relates to a control for use in conjunction with astrip-processing device such as a rolling mill or rubber or papercalender and, more particularly, to a control designed to permitprocessing under a controlled pressure.

In certain types of rolling mill practice, as well as in other similarapparatuses, it is highly advantageous to roll under a controlledpressure as opposed to the more traditional manner of rolling to aspecified percentage of reduction of the thickness of the enteringmaterial. For example, in temper rolling, to obtain optimum stripmetallurgy, it has been found advantageous to control closely thepressure to which the strip being rolled is subject during the process.Also, in the rolling of thin aluminum strip, great advantage can begained in reducing the strip in a manner in which the pressure ofreduction is controlled and kept within a specified narrow range.

Another advantage derived from rolling by pressure is the opportunity ofcompensating for inherent differential loading on the different sides ofthe mill. For example, should the rolls on the coupling end, because oftheir additional Weight, present a particular problem, it is possible tocompensate for this unequal load condition so as to obtain uniformpressure across the face of the mill rolls.

It is an object of the present invention to provide a control for use,for example, in conjunction with a rolling mill or like device, wherebypiston cylinder assemblies are provided for adjusting the rolls, inwhich connection the control will provide an arrangement whereby thepressures on either side of the rolls can be predeterminately controlledat a specified value Which can be the same or different and wherein,should differential pressures be desired, these pressures, onceestablished, can be raised and lowered Without disturbing thedifferential relationship between them.

It is another object of the present invention to provide, in conjunctionwith at least a pair of relief valves, a control valve mechanism whichwill permit simultaneous adjustment of the relief valves, whereby thepressure controlled by each valve can be raised and lowered in unison orthe controlled pressure varied to a predetermined value and thenmaintained in this relationship, notwithstanding the pressures may bechanged further in unison.

It is another object of this invention to provide in conjunction with apair of relief valves, a mechanical valve adjustment mechanism forcarrying out the immediately preceding object.

These objects, as Well as various other features of the presentinvention, will be better understood when the following description isread along with the accompanying drawings of which:

FIGURE 1 is a schematic view of a rolling mill, including the hydrauliccircuit for the roll adjusting piston cylinder assemblies of the rollingmill,

FIGURE 2 is a plan view, partially in section, of the relief valves andcontrol mechanism forming a part of the hydraulic system illustrated inFIGURE 1,

FIGURE 3 is a sectional view taken along lines III- III of FIGURE 2,

FIGURE 4 is a sectional View taken along lines IV- IV of FIGURE 2, and

FIGURE 5 is a sectional view taken along lines V-V of FIGURE 2.

With reference to the drawings and first to FIGURE 1., there isillustrated in schematic form a 4-high strip rolling mill 11 comprisinga pair of Work rolls 12 which are supported in the usual manner byindividual backup rolls 13, the rolls being received in housings 14 and15 of the mill 11. Reference to the various other well-known componentsof the rolling mill will not be made since such is not deemed necessaryto understand the present invention. It will be noted with respect tothe mill, however, that at the bottom of the housings 14 and 15, thereare provided for adjusting the two lower rolls 12 and 13, individualpiston cylinder assemblies 16 and 17. These piston cylinder assemblies,as illustrated in FIG- URE 1, are single-acting assemblies in whichconnection at their bottoms there are provided ports 18 to whichhydraulic lines 19 and 20 are connected. As shown, the lines 19 and 20are connected to separate two-way pumps 21 which are connected, in turn,to a common electrical motor 22. The lines 19 and 2d are also separatelyconnected to separate relief valves 23 and 24, respectively, the reliefvalves, as shown, having a common drain line 25 which is led into a tank26. Connected to a common side of the relief valves 23 and 24, there isa dual valve control unit 27. As FIGURE 1 shows, the relief valve 23services the piston cylinder assembly 16 while the valve 24 services theassembly 17.

It will be appreciated that While the hydraulic system has beenpurposely kept simple to facilitate a quick understanding of theillustrated embodiment of the present invention, the hydraulic systemwill include various other components, such as, two-way valves, pressuregauges, oil coolers, etc. depending on the particular installation. Therelief valves 23 and 24 are themselves a well-known commercial unit. Theparticular valves illustrated are manufactured by Vickers 1110.,Detroit, Michigan, United States of America, the basic components andoperation being clearly set forth in US. Patent No. 2,388,820 whichissued to G. C. Bonnell on November 13, 1945, entitled Relief Valve forPower Transmissions.

As shown in FIGURE 3, and in identifying the salient components of thevalves 23 and 24, they each consist of a housing 31 which has in itsupper portion a pressure control chamber 32 into which there is receiveda tension spring 33 for urging a plug 34; into an orifice 35. The otherend of the spring is connected to a rod 36 of the dual valve controlunit 27 and to which more particular reference Will be made hereinafter.The orifice 35 communicates with a chamber 37 formed in the housing 31into which chamber there is received at the lower end of the housing anaxially movable piston 38. The one end of the piston 33 engages a seat3') against which it is urged by a spring 41 received in the housing 31.Communicating with the chambers 32 and 37 is a third chamber 42, afourth chamber 43 is actually formed at the right-hand side of thepiston 38 which communicates with the chamber 37 by a port 43a formed inthe piston 38. The valve at the base, as shown, has three ports, namely44, 45, 46 in which connection the port 45 is the pressure port, theport 46 the return port and the port 44 the controlled vent or blockedport.

In operation, when the pressure in the chambers 37 and 43 are balancedand the piston 38 is seated against the seat 39, no fluid will escapethrough the orifice 35, assuming that the force of the springs 33 isgreater than the balance pressure in the chambers 37 and 43. When thepressure in the chamber 37 increases in excess of the resistance offeredby the spring 33, then the fluid is allowed to escape through theorifice 35 so that the pressure in the chamber 37 will be less than thepressure in the chamber 43. This will allow the piston 38 to move towardthe left as one views FIGURE 3 against the resistance offered by thespring 41 and the end will free itself from the seat 39, therebyallowing fluid to be discharged into the chamber 42. Also, the fluidthat passes through the orifice 35 will find its way into the chamber 42and be discharged from the return port 46.

With reference now FIGURES 2, 3, 4 and which relate, as previouslymentioned, to the dual valve control unit 27, this unit consists of ahousing 51 which, as FIG- URE 2 shows, is carried by a base 52 and towhich it is secured by four bolts 53 and by which means it is adjustabletoward and away from the relief valves 23 and 24.

In first referring to the gear train that provides for simultaneous andequal adjustment of the relief valves 23 and 24, reference will be madeto FIGURE 2 where there is shown a hand wheel 56 which is rotatablysupported in the housing 51 and to which there is connected a longrotatable shaft 57 that extends entirely through the housing 51. Theopposite end of the shaft 57 is connected by an adapter 58 to the shaft36 of the valve 24. To the shaft 57 at the end adjacent to the handwheel 56 there is secured a gear 61 which is connected to the shaft by akey 62, the arrangement being such as to assure that there will be norelative rotational movement between the gear 61 and the shaft, but theshaft will be allowed to move axially relative to the gear 61. Exceptfor the hand wheel, an identical shaft-gear arrangement is provided atthe other side of the housing 51 where, as shown in FIGURE 2, there isprovided a rotatable shaft 63 which extends through the housing 51 andhas at its other end an adapter 64 which connects the shaft 63 totheshaft 36 of the relief valve 23. The shaft 63, at the end adjacent thehand wheel 56, has secured thereto a gear 65 which is connected to theshaft 63 by a key 66, the arrangement being such that relativerotational movement between the gear 65 and the shaft 63 is prohibited,but the shaft is allowed to move axially relative to the gear 65. Inmeshing relationship with both of the gears 61 and 65 there is a pinion67 located so that its axis falls below the common plane containing theaxes of the gears 61 and 65 which relationship is best shown in FIGURE5. The pinion 67, as shown in FIGURE 4, is provided with end bushings 68and 69 which are received in the housing 51, the pinion 6'7 beingsupported by the bearings by means of a non-rotatable shaft 70.

As shown in FIGURES 4 and 5, a latch is provided for preventing rotationof the gears 61 and 65 and in this connection there is provided anon-rotatable shaft 71, which at its lower end is provided with aportion 72 having a series of teeth that engage with the upper teeth ofthe pinion 67. Above the portion 72, there is provided two axiallyspacedapart collars 73 between which there is arranged a spring 74 whichtends to urge the shaft 71 downwardly. The upper portion of the shaft 71that protrudes through the housing 51 is connected to a lever 75 whichis arranged substantially perpendicular to the axis of the shaft 71. Thelever 75 is connected toward its one end to a stand 76 which isconnected to the housing 51. The lever has a handle 78 which on thedepression thereof causes the shaft to raise against the force of thespring 74 to disengage the teeth of the shaft portion 72 from the teethof the pinion 67. Of course, once the handle 78 is released, the springwill force downwardly the shaft 71 into its locking position.

In now referring to the gear train that provides for adjustment of thevalves 23 and 24 in opposite directions, reference again is made toFIGURE 2. It will be noted with respect to the shafts 57 and 63 thatthey are provided with threaded portions 81, 82, respectively, and inthreaded engagement therewith are worm gear wheels 33 and 84,respectively, these gear wheels meshing with a common Worm that extendsin a vertical direction relative to the axes of the shafts 5'7 and 63.As shown in FIGURE 4, the worm 85 is secured to a shaft 86 which isrotatably received in the housing 51 in bushings 87 and 88 retained inthe housing by keeper plates 82, and 91. At the top of the shaft 86,there is provided a hand wheel 92 by which means the shaft 86 and wormS5 and, hence, the gears 84 and 83 are rotated, the latter being rotatedin opposite directions to each other whereby causing the shafts 57 and63 to move axially in opposite directions through the agency of theirthreaded portions 81 and 82.

Associated with the relief valves 23 and 24 are pressure gauges 93 and94 arranged in close proximity to the valve control unit 27 so that theoperator will be apprised at all times of the pressures in the twocylinders 16 and 17.

A brief description of the operation of the present invention will nowbe given with respect to the control of the pressure in the pistoncylinder assemblies 16 and 17 of the mill 11. Assuming that the relativepositions of the gearing are such as to impose identical compressionforces on the two springs 33 of the relief valves 23 and 24 and it isdesired to raise the pressure, yet maintaining equal the pressure in thelines 19 and 20, then, in that event, the latch is released to permitrotation of the gears 61 and 65 by depressing the handle 78 to raise theshaft 71, whereby the teeth of the pinion 67 are disengaged from theteeth of the portion 72 of the shaft 71. After this the hand wheels 56may be rotated which'will rotate the gears 61 and 65 in unison causingsimilar rotation of the shafts 57 and 63 whereby the rods 36 of therelief valves ..3 and 24 will be d'splaced an equal amount commensuratewith the new desired pressures, as indicated in the gauges 93 and 94.

Should it be desired to operate under a differential pres sure conditionwhereby, for example, only the pressure in the piston cylinder assembly17 is to be increased, with the gears 61 and 65 in their lockedposition, the hand wheel $2 will be rotated the desired amount to obtainthe desired differential pressure condition as reflected by the gauges93 and 94 associated with the relief valves 23 and 24. Of course, it maybe necessary to again operate the hand wheel 56 to obtain the precisepressure for each cylinder 16 and 17.

In accordance with the provisions of the patent statutes, I haveexplained the principle and operation of my invention and haveillustrated and described what I consider to represent the bestembodiment thereof. However, I desire to have it understood that withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically illustrated and described.

I claim:

1. In a fluid control system for a rolling mill or the like apparatushaving at least a pair of rolls, including apair of piston cylinderassemblies arranged at the opposite ends of one of the rolls of the millto cause said one 5 roll to move towards and away from the other roll ofthe pair, the improvement comprising:

a relief valve connected to each of said piston cylinder assemblies,including displaceable members for controlling the pressure of the fluiddelivered to said piston cylinder assemblies,

said displaceable members being received in pressure control chambersformed in said valves which include spring-biased control plugs,

a pair of rotatably mounted, axially displaceable shafts, one of saidshafts being connected to one of said control plugs and the other shaftbeing connected to the other of said control plugs,

first gearing mounted on said shafts for causing rotation thereof,

a Worm arranged to interconnect said shafts through said first gearing,

means for rotating said first gearing and worm to effect rotation ofsaid shafts in opposite directions to establish an unequaled outputpressure of the fluid delivered from said valves,

second gearing mounted on said shafts for causing rotation thereof,

a pinion arranged to interconnect said shafts through said secondgearing,

cluding a locking means for preventing rotation of one of said gearing,and

means for rendering said locking means inoperative to allow rotation ofsaid one gearing.

References Cited UNITED STATES PATENTS 581,078 4/ 1897 Menne 72-2452,678,465 5/ 1954 Schnook et al. 72--245 3,024,679 3/1962 Fox 722453,039,513 6/ 1962 Lasiewicz 728 FOREIGN PATENTS 647,606 12/1950 GreatBritain.

CHARLES W. LANHAM, Primary Examiner. 25 A. RUDERMAN, Assistant Examiner.

1. IN A FLUID CONTROL SYSTEM FOR A ROLLING MILL OR THE LIKE APPARATUSHAVING AT LEAST A PAIR OF ROLLS, INCLUDING A PAIR OF PISTON CYLINDERASSEMBLIES ARRANGED AT THE OPPOSITE ENDS OF ONE OF THE ROLLS OF THE MILLTO CAUSE SAID ONE ROLL TO MOVE TOWARDS AND AWAY FROM THE OTHER ROLL OFTHE PAIR, THE IMPROVEMENT COMPRISING: A RELIEF VALUE CONNECTED TO EACHOF SAID PISTON CYLINDER ASSEMMBLIES, INCLUDING DISPLACEABLE MEMBERS FORCONTROLLING THE PRESSURE OF THE FLUID DELIVERED TO SAID PISTON CYLINDERASSEMBLIES, SAID DISPLACEABLE MEMBERS BEING RECEIVED IN PRESSURE CONTROLCHAMBERS FORMED IN SAID VALVES WHICH INCLUDE SPRING-BIASED CONTROLPLUGS, A PAIR OF ROTATABLY MOUNTED, AXIALLY DISPLACEABLE SHAFTS, ONE OFSAID SHAFTS BEING CONNECTED TO ONE OF SAID CONTROL PLUGS AND THE OTHERSHAFT BEING CONNECTED TO THE OTHER OF SAID CONTROL PLUGS, FIRST GEARINGMOUNTED ON SAID SHAFTS FOR CAUSING ROTATION THEREOF, WORM ARRANGED TOINTERCONNECT SAID SHAFTS THROUGH SAID FIRST GEARING,